function toggleLayer(obj1,obj2) {
	var el = document.getElementById(obj1);
	if ( el.style.display != 'none' ) {
		el.style.display = 'none';
	}else{
		el.style.display = '';
		if (obj2) {
		 	 var el = document.getElementById(obj2);
		 	 el.style.display = 'none';
	  }
	}
}